Wyniki wyszukiwania - Biblioteka Nauki

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Molecular dynamics simulation of manipulation of metallic nanoclusters on stepped surfaces

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Mahboobi S. , Meghdari A. , Jalili N. , Amiri F.

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tom 9

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nr 2

454-465

EN

Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on stepped surfaces. Five surface forms are considered in the simulations. The system parts are made of pure transition metals and Sutton-Chen many-body potential is used as interatomic potential. The conditions which are subjected to change in the tests include: materials used for particles and substrate, and surface step conditions. In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Simulation results show the effect of the aforementioned working conditions on the particle behavior as well as changes in the pushing forces. Obtaining this sort of knowledge is highly beneficial for further experiments in order to be able to plan the conditions and routines which guarantee better success in the manipulation process.

2

Graphene hydrogels with embedded metal nanoparticles as efficient catalysts in 4-nitrophenol reduction and methylene blue decolorization

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Żelechowska K. , Kondratowicz I. , Gazda M.

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tom Vol. 18, nr 4

47--55

EN

Synthesis and characterization of the graphene hydrogels with three different metallic nanoparticles, that is Au, Ag and Cu, respectively is presented. Synthesized in a one-pot approach graphene hydrogels with embedded metallic nanoparticles were tested as heterogeneous catalysts in a model reaction of 4-nitrophenol reduction. The highest activity was obtained for graphene hydrogel with Cu nanoparticles and additional reaction of methylene blued degradation was evaluated using this system. The obtained outstanding catalytic activity arises from the synergistic effect of graphene and metallic nanoparticles. The hydrogel form of the catalyst benefits in the easiness in separation from the reaction mixture (for example using tweezers) and reusability.

3

Absorption Enhancement in Si Solar Cells by Incorporation of Metallic Nanoparticles: Improved COMSOL Numerical Study Including Quantum Corrections

100%

Kluczyk K. , Krzemińska Z. , Jacak W.

Acta Physica Polonica A

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2017

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tom 132

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nr 2

393-397

EN

One of the crucial parameters affecting the solar cell efficiency is the absorption rate versus solar spectrum. Metallic nanoparticles deposited on the cell surface can mediate this process. Main mechanisms of absorption enhancement due to metallic nanoparticle plasmons were proposed: (1) the scattering of incident solar light causing increase of the optical path length inside active layer and local enhancement of the electric field; (2) near field coupling between plasmon and semiconductor and the direct generation of electron-hole pairs in the semiconductor. The field concentration effect can be described by classical electrodynamic theory, the coupling between metallic nanoparticle plasmons and band electrons in semiconductor substrate must be captured upon quantum mechanics. In this paper we took the challenge to develop fast and reliable method for calculation of device optical properties by application of COMSOL system appropriately configured to take into account these quantum effects, via the quantum modification of the dielectric function of semiconductor substrate and metallic components. The presented results indicate that the efficiency of energy transfer due to near field coupling of metallic nanoparticle plasmons with semiconductor substrate is much more effective than the absorption increase due to metallic nanoparticle plasmons scattering only.

4

Potecjał aplikacyjny nanometali w ochronie środowiska

63%

Malina D.

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2017

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tom Vol. 18, nr 1

111--117

PL

W ostatnich latach obserwuje się duże zainteresowanie nanocząstkami metalicznymi, zarówno ze względu na ich nieograniczone możliwości aplikacyjne, a także z uwagi na niezwykłe cechy biologiczne, chemiczne i fizyczne. Przewiduje się, że osiągnięcia nanotechnologii staną się głównym promotorem innowacji naukowych i technologicznych w najbliższych dekadach. Poszukując nowej i bezpiecznej alternatywy w stosunku do chemicznych pestycydów, duże nadzieje wiąże się właśnie z rozwojem nanotechnologii. Szczególnie przydatne mogą okazać się preparaty zawierające nanometryczne cząstki metali o silnych właściwościach przeciwdrobnoustrojowych. Co ważne, do otrzymywania nanocząstek nanometali można zastosować bezpieczne i nietoksyczne dla roślin komponenty pochodzenia biologicznego. Niniejszy artykuł jest opisem potencjalnych możliwości aplikacyjnych nanomateriałów w ochronie środowiska, które mają szansę stać się podstawą do opracowania nowych środków ochrony roślin o właściwościach przeciwdrobnoustrojowych w stosunku do patogenów roślinnych oraz jednocześnie nietoksycznych dla organizmów wyższych.

EN

In recent years, great interest in metallic nanoparticles has been observed, both because of their unlimited application possibilities, and also because of the unusual biological, chemical and physical features. It is expected that developments in nanotechnology will become the main promoter of scientific and technological innovations in the coming decades. Searching for a new and safe alternative to chemical pesticides, high hopes are associated with nanotechnology development. Particularly useful may be preparations containing nanoscale metal particles with strong antimicrobial properties. Importantly, safe and non-toxic for the plant components of biological origin may be used in nanoparticles synthesis. This article is a description of the potential applications of nanomaterials in environmental protection, which may become the basis for developing of new protection plant products with antimicrobial properties relative to plant pathogens and non-toxic to higher organisms.